Water cannon

ABSTRACT

A water cannon utilizing ultra high pressure to propel a collimated beam of water or other liquid through a nozzle at high speeds at great distances. Ultra high pressure is achieved by multiple serially communicating pumping stations that successively build fluid pressure within respective annular chambers having cross-sectional areas that decrease between the pumping stations as fluid speed increases in the downstream direction. To attain the desired velocity head at the nozzle, a gearbox connected to a prime mover, e.g., a gas turbine engine on-board an ocean vessel, drives multi-stage axial flow pumps at successively increasing speeds commensurate with a volumetric rate of flow. Optionally, the axial flow pumps may include variable stator vanes between rotor blades and/or variable inlet guide vanes at an inlet in order to control flow volume, fluid pressure, engine load, or impact force delivered by the cannon. Further, the collimated beam exiting the cannon may be electrified with a high voltage in order to disable the target&#39;s on-board processing or communication equipment. Depending on design criteria, beam size (e.g., three to six inches, more or less), ejection speed, ejection pressure (e.g., 3,000 to 10,000 psi), flow rate (several hundred to several thousand pounds per second), and/or range (e.g., two to five miles) may be adjusted to achieve a desired effect on a target.

CROSS-REFERENCE TO RELATED PATENTS AND PATENT APPLICATIONS

This invention claims the benefit of provisional application Ser. No.60/606,904 filed in the names of the inventors hereof on Sep. 3, 2004and entitled “Water Cannon Weapon and Defense System.

This invention is also related to U.S. application Ser. No. 10/801,705filed in the name of Donald Cornell on Mar. 17, 2004 and entitled “AxialFlow Pump and Marine Propulsion Device,” which is incorporated herein byreference.

BACKGROUND

The present invention relates to a water cannon that may be used forirrigation, fire or flood control, large area decontamination, or as aweapon or defense mechanism against incoming missiles or projectiles.

Historically, such devices have been used for close-range defense,firefighting, irrigation, and crowd control by propelling a collimatedbeam or spray of water. For many applications, prior systems at bestwere marginally effective due to the inability to pump large volumes ofwater at ultrahigh pressures of a few thousand psi (pounds per squareinch). Operating pressures of conventional centrifugal, axial flow, andmixed-flow pumps having a flow rate of more than a few hundred poundsper second were limited to a few hundred pounds-per-square inch (psi).Such pumps also traded off water pressure with flow volume, or viceversa. Displacement pumps, although producing ultrahigh pressures of10,000 psi or more pumped only infinitesimal amounts of water incomparison to other pump types.

Due to extremely high flow rates of a few hundred pounds of water persecond (or more) and extremely high pressures of a few thousand psi (ormore), the present invention may be used as a more effective firecontrol or irrigation/flood control device; a more effective weapon tofend off small vessels at a greater range than heretofore possible; anartillery mechanism; an excavation tool; a mine sweeping device; or as adefense mechanism to disable or blind incoming missiles or “smart”projectiles by drowning out their turbojet propulsion, disrupting itstrajectory path by water mass impact, or shielding against any on-boardIR tracking and targeting.

SUMMARY

To achieve the above-mentioned objectives, the present inventioncomprises a water cannon utilizing ultra high pressure to propel acollimated beam of water or other fluid through a collimating nozzle atsuch high speeds (e.g., mach speeds) in order to project water to agreater distance (e.g., several thousands of feet) or to pierce steel,concrete, or other materials of a target at a closer range. Thecollimating nozzle, if employed, may be designed to maintain fluidcoherency and/or to minimize dispersion of the collimated beam ofliquid.

An ultra high discharge pressure required for high fluid velocity isachieved by deploying multiple axial flow pumping stations thatsuccessively build fluid pressure within annular chambers of each pumpas well as between pumps. The cross-sectional area of the respectiveannular chambers may decrease between pumps as fluid speed increases inthe downstream direction. Each pumping station comprises a multi-stageaxially flow pump that may have variable pitch stator vanes and fixedpitch rotor blades. Optionally, the rotor blade pitch may be variable.In addition, the serially communicating pumping stations may bephysically arranged in parallel with U-shaped conduits between thestations, or serially (in-line) arranged with interconnecting conduitsbetween the stations. The U-shaped bends in the conduits may alsoprovide moment cancellation to help stabilize an aiming platform for thenozzle. Taps may be located at successive stations to draw a volume andpressure of water generated at the respective stages.

To attain a desired velocity head at the discharge nozzle, a gearboxconnected to a multi-megawatt power source, e.g., a gas turbine engineon-board an ocean vessel or an electric motor driven by land-based powerstation, drives the multi-stage axial flow pumps within the respectivepumping stations at successively increasing speeds. Optionally, theaxial-flow pumps may include variable inlet guide vanes at their inletsin order to control flow volume, fluid pressure, engine load, and/orimpact force delivered by the cannon. The fluid may also include solidprojectiles, abrasives, or chemical additives. Further, the collimatedbeam of water or other fluid exiting the cannon may be electrified witha high voltage in order to disable the target's on-board processing orcommunication equipment. Depending on design criteria, beam size (e.g.,four to six inches, more or less), water ejection speed (300 to 2000feet/second or more), ejection pressure (e.g., 2,000 to 10,000 psi moreor less), mass flow rate (several hundred to several thousand pounds persecond), and/or range (e.g., 3,000 to 20,000 feet, more or less) may beadjusted to achieve a desired goal or impact on a target.

Another embodiment of the invention comprises a method of ejecting highpressure liquid from a nozzle comprising the steps of providing at leastthree serially-communicating multistage axial flow pumps having liquidflow paths therein of decreasing diameters in a downstream direction,operating the pumps to increase liquid pressure between successivepumps, conveying liquid between successive pumps along a path having adecreasing cross-sectional area in the downstream direction whereby tocorrespondingly increase speed of said liquid along the path, andejecting the liquid from a nozzle communicating with a final one of saidserially communicating pumps. The method of claim 15, further comprisingthe step of collimating said liquid prior to said ejecting step in orderto reduce dispersion after said ejecting. The method may includecollimating the liquid prior to ejecting in order to reduce dispersionafter ejecting, controlling at least one of a direction and azimuth ofejection of the liquid during ejecting, gearing a common shaft to rotatethe serially communicating axial flow pumps at different speedscommensurate with a volumetric rate of flow, or physically arranging theserially communicating pumps to cancel moments generated by accelerationof liquid mass through said pumps.

Other aspects of the invention will become apparent of review of thefollowing description taken in connection with the accompanyingdrawings. The invention, though, is pointed out with particularity bythe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a first arrangement of serially communicating in-line axialflow pumps, drivers, and interconnecting conduits to produce ultrahigh-pressure water ejection.

FIG. 2 shows a second arrangement of serially communicating byphysically parallel arranged axial flow pumps, drivers, andinterconnecting conduits to produce ultra high-pressure water ejection.

FIG. 3 illustrates an effective missile kill range of an ultrahigh-pressure water cannon deployed on a vessel.

FIG. 4 illustrates yet another embodiment of axial flow pumps arrangedto cancel opposing moments generated by acceleration of liquid massthrough the pumps in order to reduce overall disturbances indisplacement when operating the water cannon system.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 shows water cannon device comprising a serially arranged group ofpumping stations 12, 14, and 16, each comprising a multistage axial-flowpump similar to that disclosed in the aforementioned, commonly-owned,incorporated U.S. patent application Ser. No. 10/801,705. The exemplarywater cannon of FIG. 1 has a flow rate of about 900 pounds of water persecond and a pressure of 3600 to 6000 psi at the discharge nozzle.According to design criteria, it is projected to propel a four inchcollimated beam of water about 15,000 feet vertically and 31,000 feethorizontally, depending on azimuth of ejection, as shown in FIG. 3. Atank 18 provides an inlet to pumping station 12, which is driven viagearbox 22 and drive shaft 24 by an electric motor 20 producing, forexample, 500 horsepower, to drive the pump at about 2000 revolutions perminute (rpms). Instead of a tank, the inlet of station 12 may be feddirectly from an ocean, lake, river, or water reservoir. Pumping station12 may optionally include a tap 26 as well as a valve to provide anauxiliary output should the pressure of station 12 to provide adequateflow for a particular application, e.g., lower pressure (e.g., 100 psimore or less) at a much higher volume. In one embodiment, pumpingstation 12 comprises seven rotor-stator sections and variable inletguide vanes. In addition, rotor or stator vanes of pumping station 12may be variable to regulate pressure and flow rate.

Similarly, pumping station 14, which builds upon the fluid pressuregenerated by pumping station 12, includes a motor 30 that drives amultistage axial-flow pump via gearbox 32 and shaft 34. The exemplarymotor 30 produces 40,000 horsepower to drive the second stage pump atabout 9600 rpms. Pumping station 14 also includes an auxiliary tap 36and valve to provide a pressure, for example, of 850 psi. Aninterconnecting conduit 40 between stations 12 and 14 has a decreasingcross-sectional area to accommodate an increase in flow speed as thewater transgresses the pumping stations. The smaller diametermulti-stage pump at station 14 spins at a faster rate, e.g., around 9600rpms, than the pump at station 12. A third pumping station 16 alsoincludes a multi-stage axial flow pump, a motor 44, gearbox 46, anddrive shaft 47. In the exemplary embodiment, the exemplary motor 44produces 30,000 horsepower to drive the axial flow pump at about 22,000revolutions per minute to produce a pressure of 3600 to 6000 psi. One ormore engines of an ocean vessel, a land-based power grid, or a gasturbine engine may power motor 30.

Conduit 42 between stations 14 and 16 defines a fluid path thatdecreases in cross-sectional area in the downstream direction as thespeed of the water increases. Conduit 43 between station 16 and thenozzle is preferably constant in cross-sectional area and also includesan auxiliary tap 37 and valve. Alternatively, conduit 43 may also definea path having decreasing cross-sectional area in the downstreamdirection. Nozzle 50, preferably mounted on a turret, has an azimuthcontrol and rotates 360 degrees. For safety reasons, an operator in aprotected cage remotely controls the nozzle. Nozzle designs known in theart are employed to collimate the water beam, create a mist or spray, orprovide a desired dispersion. Additives may be included in mixing tank18 via chemical feed tank 60 to enhance conductivity or other propertiesof the collimated water beam.

FIG. 2 shows an alternative design where pumping stations 12, 14, and 16are physically arranged in parallel (but flow still being cascaded), anda common gearbox 60 is provided to drive the respective pumping stationsat different speeds.

FIG. 3 illustrates a possible range or coverage area of the water cannonweapon mounted on a vessel 68 having nozzle 70 to propel a coherent orcollimated beam of sea water throughout a kill radius shown by hatchedarea 71. In the illustrated embodiment, a water spray 69 about fourinches at the nozzle 70 is propelled approximately three milesvertically and about five-six miles horizontally. The water cannon maybe powered by on-board propulsion units of the vessel 68 or byindependent power plants. If land-based, the water cannon may be poweredby the electrification grid or by a mobile power plant such as a gasturbine. Various nozzle designs may be employed, depending on thepurpose of use. In addition, gearing need not be use to drive themultistage axial flow pumps. In certain designs, the pump may bedirect-driven by the drive shaft without gearing.

FIG. 4 shows yet another embodiment comprising a gearbox 60 that gears acommon shaft 81 driven by a prime mover producing approximately 99,000horse power (145,000 foot-pounds of torque at 3600 rpms) to rotateserially communicating axial flow pumps 72, 74, 76, and 77 via shafts82, 83, and 84. Shaft 84 turns at 2000 rpms, shaft 83 turns at 11,000rpms, and shaft 82 turns at 43,000 rpms. Shaft 82 drives both pumps 76and 77 at 43,000 rpms. The diameters of annular chambers in therespective pumps and their respective rotational speeds enable a givenflow rate of, for example, 53,000 gallons per minute, and a waterejection speed from nozzle 70 of about 400 mph. The cross-sectional areaof the interconnecting conduits 87 and 88 decrease in the downstreamdirection to match the diameter of the follower pump. Conduit 89 isprovided to reverse the liquid flow 180 degrees in order to offsetopposing forces generated by accelerating the mass of liquid in pumpingstages 76 and 77. Advantageously, opposing moments developed by pumps 76and 77 are cancelled to as avoid disturbance of any aiming mechanismsfor the nozzle. Similarly, opposing moments generated by liquid massacceleration in pumps 72 and 74 are also cancelled.

Without regard to structure, another embodiment of the inventioncomprises a method of ejecting high pressure liquid, e.g., water, from anozzle. Such a method comprises the steps of providing at least threeserially-communicating multistage axial flow pumps having liquid flowpaths therein of decreasing diameters in a downstream direction,operating the pumps to increase liquid pressure between successivepumps, conveying the liquid between successive pumps along a path havinga decreasing cross-sectional area in the downstream direction whereby tocorrespondingly increase speed of the liquid along the path, andejecting said liquid from a nozzle communicating with a final one ofsaid serially communicating pumps. Variations may include the step ofcollimating said liquid prior to the ejecting step in order to reducedispersion after said ejecting; controlling the direction or azimuth ofejection of the liquid during the ejecting step; gearing a common shaftto drive or rotate the serially communicating axial flow pumps atdifferent speeds commensurate with a volumetric rate of flow; orphysically arranging the serially communicating pumps to cancel momentsgenerated by accelerating liquid mass through said pumps.

Various other embodiments may become apparent to those skilled in theart based on the teachings herein. Thus, the illustrated embodiments arenot intended to limit the invention defined by the appended claims.

1. A water cannon comprising: an inlet, a first pumping station having a first multistage axial flow pump, a second pumping station having a second multistage axial flow pump, a primary conduit disposed between the first and second pumping stations having a cross-sectional area the converges in a downstream direction, a third pumping station having a third multistage axial flow pump, a secondary conduit between the second and third pumping stations having a cross-sectional area the converges in a downstream direction, and a nozzle that includes a flow straightener that receives water from the third pumping station to produce a coherent beam of fluid.
 2. The water cannon of claim 1, comprising independent drive shafts to drive rotor blades in the respective axial flow pumps of the pumping stations and a gearing mechanism coupling an engine to rotate each shaft at a speed commensurate with desired fluid velocity within the respective pumping stations.
 3. The water cannon of claim 2, wherein said pumping stations are disposed substantially in physically parallel relation and said primary and secondary conduits are U-shaped.
 4. The water cannon of claim 2, wherein said pumping stations are substantially axially aligned with substantially axially disposed primary and secondary conduits between said pumping stations.
 5. The water cannon of claim 1, further including a terminal conduit between the third pumping station and the nozzle that converges towards said nozzle whereby to further increase velocity of ejected water.
 6. The water cannon of claim 5, further comprising a turret that controls direction of said nozzle about a vertical axis and an azimuth of said nozzle about a horizontal axis.
 7. The water cannon of claim 1, wherein said nozzle produces a collimated beam of fluid greater than 100 mm in diameter and said first, second, and third pumping stations include an arrangement of rotors and stators to successively build fluid pressure beyond 3000 psi at said nozzle.
 8. The water cannon of claim 1, further including a venturi injector in a flow path of said fluid to add a substance to said fluid prior to ejection from said nozzle.
 9. The water cannon of claim 1, wherein said axial flow pumps include variable stator vanes within multistage sections thereof whereby to control loading and fluid flow rate within the axial flow pumps.
 10. The water cannon weapon of claim 9, wherein said stator vanes of said axial flow pumps are independently controllable.
 11. The water cannon of claim 1, wherein at least said first axial flow pump includes a variable inlet guide vane at an inlet thereof.
 12. A device that generates ultra high fluid pressure, said device comprising: a fluid inlet; multiple serially communicating pumping stations that each comprise a multistage axial flow pump, each said axial flow pump including multiple rotor sections and stator sections; a conduit between each pumping station having a decreasing cross-sectional area in a downstream direction, and a flow straightener to convey a coherent beam of fluid from a final pumping station to an outlet.
 13. The device of claim 12, further comprising an independent drive shaft for each pumping station.
 14. The device of claim 13, further including an engine having a main shaft and a gearbox coupled to the main shaft of the engine and each said independent shaft in order to rotate each independent shaft at a speed commensurate with a given rate of mass flow of liquid.
 15. A method of ejecting high pressure liquid from a nozzle comprising the steps of: providing at least three serially-communicating multistage axial flow pumps having liquid flow paths therein of decreasing diameters in a downstream direction, operating said pumps to increase liquid pressure between successive pumps, conveying said liquid between successive pumps along a path having a decreasing cross-sectional area in the downstream direction whereby to correspondingly increase speed of said liquid along the path, and ejecting said liquid from a nozzle communicating with a final one of said serially communicating pumps.
 16. The method of claim 15, further comprising the step of collimating said liquid prior to said ejecting step in order to reduce dispersion after said ejecting.
 17. The method of claim 16, further comprising the step of controlling at least one of a direction and azimuth of ejection of said liquid during said ejecting step.
 18. The method of claim 17, further comprising the step of gearing a common shaft to rotate said serially communicating axial flow pumps at different speeds commensurate with a volumetric rate of flow.
 19. The method of claim 17, further comprising physically arranging said serially communicating pumps to cancel moments generated by accelerating liquid mass through said pumps. 